Trusted Computing is a security technology in computing systems, developed and promoted, for example, by the Trusted Computing Group (TCG). With trusted computing, the behavior of a computer is enforced by applying cryptographic and other security techniques. For example, U.S. Patent Application Publication 2005/0021968, whose disclosure is incorporated herein by reference, describes a method for providing a secure firmware update. A first authentication credential is securely stored on a platform in an encrypted form using a key generated by a secure token, such as a trusted platform module (TPM). A configuration of the platform is “imprinted” such that an identical configuration is required to access the key used to decrypt the first authentication credential by sealing the key against the platform configuration. During a subsequent firmware update process, a firmware update image containing a second authentication credential is received at the platform. If the platform configuration is the same as when the key was sealed, the key can be unsealed and used for decrypting the first authentication credential. A public key in the first authentication credential can then be used to authenticate the firmware update image via the second authentication credential.
As another example, U.S. Patent Application Publication 2003/0061494, whose disclosure is incorporated herein by reference, describes a method and system for protecting data on a computer. A computer is provided that has a pre-operating system (pre-OS) space and an operating system-present (OS-present) space. Protected storage is accessed from pre-OS space via a trusted platform module (TPM). Similarly, protected storage is accessed from OS-present space via the TPM. As such, from both pre-OS space and OS-present space, a computer may prevent unauthorized users from gaining access to data stored in protected storage.